t/modules/http2.t: Run only if OpenSSL >= 1.0.0 is available

Am 18.10.2018 um 14:23 schrieb Stefan Eissing:

Am 18.10.2018 um 14:12 schrieb Rainer Jung <rainer.jung@xxxxxxxxxxx>:
- t/modules/http2.t fails when the server is build using OpenSSL 0.9.8zh with the "Bad plan. You planned 52 tests..." message indicating, that h2 using TLS does not work. It happens on all platforms, but not if the client also uses OpenSSL 0.9.8zh.
I don't know whether that is expected for old OpenSSL, so can not judge on criticality.

AFAICT, correct me if I am wrong, OpenSSL 0.9.8 does not support TLSv1.2 and is therefore unusable with h2. The test suite seems to be unprepared for this scenario. I will remove it after the next release. It is not worth fixing in its current form.

I added a check agains the test suite OpenSSL version in r1844483.

I have an aditional check for the server version available.
Unfortunately I didn't find a really easy way, so here's a small module
that one can query (c-modules/test_ssl_version/mod_test_ssl_version.c),
mostly a shortened form of mod_test_ssl.c: